Enantiomeric determination of ephedrines and norephedrines by chiral derivatization gas chromatography–mass spectrometry approaches

Concerned with variations in abuse potential and control status among various isomers of ephedrines and norephedrines, this study was conducted to develop an effective method for the simultaneous analysis of eight ephedrine-related compounds along with structurally similar cathinones. Among various approaches studied, a 60-m HP-5MS (0.25 mm i.d., 0.25 μm film thickness) was successfully used to characterize the following compounds that were derivatized with (−)-α-methoxy-α-trifloromethylphenylacetic acid (MTPA): (+)-cathinone, (−)-cathinone, (+)-norephedrine, (−)-norephedrine, (+)-norpseudoephedrine, (+)-ephedrine, (−)-ephedrine, (−)-pseudoephedrine, (+)-pseudoephedrine. (−)-Cathine standard was not available, but should also be resolvable under this analytical procedure. This method was successfully applied to the analysis of selected cold remedies for characterizing the enantiomeric compositions of the compounds present in these samples.